椎间盘疝入胸腰段骨折椎体导致骨折畸形愈合及椎间隙高度下降

目的：分析损伤且疝入胸腰段骨折椎体的椎间盘组织对骨折愈合、椎体骨缺损体积变化及椎间隙高度影响的临床特点。方法：自2016年4月至2020年4月,行椎弓根钉棒系统复位内固定治疗140例胸腰段单椎体骨折合并上邻椎间盘损伤患者,男83例,女57例,年龄19~58（39.33±10.26）岁。术后6、12、18个月定期门诊复诊随访。损伤椎间盘组织未疝入骨折椎体患者为对照组,椎间盘损伤且疝入骨折椎体患者为观察组。通过不同回访时间下胸腰段正侧位X线片、CT及MRI扫描图像,分析计算骨折椎体楔变角、矢状位后凸角和上邻椎间隙高度变化,椎体复位后骨折愈合及骨缺损体积的变化以及椎间盘退变等级变化;并通过视觉模拟评分（visual analogue scale,VAS）、日常生活功能障碍指数（Oswestry disability index,ODI）评估患者预后;最后综合分析不同组别之间上述结果的差异性。结果：所有患者术后伤口正常愈合,无并发症发生。共87例患者获得完整回访资料,至少回访至内固定术后18个月。胸腰段正侧位X线发现观察组患者在复位内固定手术18个月后,椎体楔变角、矢状位后凸角增加及上邻椎间隙高度下降均大于对照组（P<0.05）。CT扫描发现观察组患者椎体复位术后12个月骨折畸形愈合并形成与椎间隙相通的骨缺损"空腔",且其体积较前明显增大（P<0.05）。MRI扫描发现术后12个月观察组损伤椎间盘退变率较对照组严重且差异具有统计学意义（P<0.05）。但各时间下腰背部疼痛VAS及ODI差异无统计学意义。结论：损伤椎间盘组织疝入骨折椎体,使骨折周围骨质吸收骨缺损体积增大,形成与椎间隙相通的畸形愈合"空腔",这可能是内固定装置去除后椎体楔变角、矢状面后凸角增加和椎间隙高度下降的主要原因。

Herniation of intervertebral disc into thoracolumbar fracture vertebral body leads to malunion of fracture and decrease of intervertebral space height

Objective To analyze the clinical characteristics of intervertebral disc tissue injury and herniation into the vertebral body in thoracolumbar fracture on fracture healing, vertebral bone defect volume and intervertebral space height.Methods From April 2016 to April 2020, a total of 140 patients with thoracolumbar single vertebral fracture combined with upper intervertebral disc injury treated with pedicle screw rod system reduction and internal fixation in our hospital. There were 83 males and 57 females, aged from 19 to 58 years old, with an average age of (39.33±10.26) years old. All patients were followed up regularly 6 months, 12 months and 18 months after surgery. The patients with injured intervertebral disc tissue not herniated into the fractured vertebral body were the control group, and the patients with injured intervertebral disc and herniated into the fractured vertebral body were the observation group. By detecting the thoracolumbar AP and lateral X-ray films, CT and MRI of the thoracolumbar segment at different follow-up time, calculate the changes of the wedge angle of the fractured vertebral body, the sagittal kyphosis angle and the height of the superior adjacent intervertebral space, the changes of the fracture healing and bone defect volume after the reduction of the vertebral body, and the changes of the intervertebral disc degeneration grade. The prognosis was evaluated by visual analogue scale(VAS) and Oswestry disability index(ODI). Finally, the differences of the above results among different groups were comprehensively analyzed.Results All the patients had normal wound healing with out complications. A total of 87 patients received complete follow-up data, at least 18 months after internal fixation. Thoracolumbar AP and lateral X-ray films showed that 18 months after the reduction and internal fixation operation, the vertebral wedge angle, sagittal kyphosis angle and the height of the upper adjacent intervertebral space in the observation group were greater than those in the control group(P<0.05). CT scanning showed that the deformity of the fracture healed 12 months after the vertebral body reduction in the observation group and formed a "cavity" of bone defect connected with the intervertebral space, and its volume was significantly increased compared with that before (P<0.05). MRI scanning showed that the degeneration rate of injured intervertebral discs in the observation group was more serious than that in the control group 12 months after operation(P<0.05). However, there was no significant difference in VAS and ODI score at each time.Conclusion Herniation of injured intervertebral disc tissue hernias into the fractured vertebral body leads to increased bone resorption defect volume around the fracture and forms a malunion "cavity" connected with the intervertebral space. This may be the main reason for the change of vertebral wedge angle, the increase of sagittal kyphosis angle and the decrease of intervertebral space height after removal of internal fixation devices.